Modeling Magnetohydrodynamic Energy Generation and Storage in Planetary Entry System Conceptual Design

Abstract

For a vehicle to land on a planetary body, it must first shed its kinetic energy, reducing its relative speed from multiple kilometers per second to zero. For planetary bodies with an atmosphere, aerodynamic drag is used to convert the vehicle’s kinetic energy into thermal energy, creating a high-temperature plasma in front of the vehicle. This kinetic energy is generally dissipated during the entry process and not harnessed for later use. This study aims to investigate the suitability of magnetohydrodynamic energy generation for reclaiming vehicle kinetic energy through interaction with the high-temperature entry plasma. A conceptual design methodology for estimating the energy available via magnetohydrodynamic energy generation and mass of the associated electrical energy storage system is presented. This methodology is applied to several potential mission configurations, with results that include the energy available and the performance of various electrical energy storage technologies for each case. Peak power levels of approximately 700 and 900 kW per square meter of generator area are observed for Mars and Earth entry, respectively, with available energy for storage of 60 and 30 MJ per square meter of generator area for Mars and Earth, respectively. In all but one case, this energy is capable of being stored in an electrical energy storage system with mass equal to or less than 25% of the original entry vehicle mass.